Compact jaw including split pivot pin

ABSTRACT

An end effector assembly for use with a forceps includes a pair of jaw members, a knife assembly, and one or more cam assemblies. One or more of the jaw members are moveable relative to the other about a pivot between open and closed positions. One or more of the jaw members include a knife channel. The pivot includes first and second sections defining a passage therebetween. The knife assembly includes a knife blade and an actuation shaft. The knife blade is disposed distally relative to the pivot. The actuation shaft is configured for slidable translation through the passage to allow selective advancement of the knife blade through the knife channel. The one or more cam assemblies are operably coupled to the one or more moveable jaw members and are actuatable to move the one or more jaw members between the open and closed positions for grasping tissue therebetween.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/811,451, filed Jul. 28, 2015, now U.S. Pat. No. 10,709,494, which isa continuation of U.S. patent application Ser. No. 13/933,409, filedJul. 2, 2013, now U.S. Pat. No. 9,113,609, which is a continuation ofU.S. patent application Ser. No. 12/692,414, filed on Jan. 22, 2010, nowU.S. Pat. No. 8,480,671, the entire contents of each of which areincorporated by reference herein.

BACKGROUND Technical Field

The present disclosure relates to an apparatus for performing anendoscopic electrosurgical procedure. More particularly, the presentdisclosure relates to an apparatus for performing an endoscopicelectrosurgical procedure that employs an endoscopic electrosurgicalapparatus that includes an end effector assembly configured for use withvariously-sized access ports.

Description of Related Art

Electrosurgical apparatuses (e.g., electrosurgical forceps) are wellknown in the medical arts and typically include a handle, a shaft and anend effector assembly operatively coupled to a distal end of the shaftthat is configured to manipulate tissue (e.g., grasp and seal tissue).Electrosurgical forceps utilize both mechanical clamping action andelectrical energy to effect homeostasis by heating the tissue and bloodvessels to coagulate, cauterize, fuse, seal, cut, desiccate, and/orfulgurate tissue.

As an alternative to open electrosurgical forceps for use with opensurgical procedures, many modern surgeons use endoscopes and endoscopicelectrosurgical apparatus (e.g., endoscopic forceps) for remotelyaccessing organs through smaller, puncture-like incisions. As a directresult thereof, patients tend to benefit from less scarring, less pain,and reduced healing time. Typically, the endoscopic forceps are insertedinto the patient through one or more various types of cannulas or accessports (typically having an opening that ranges from about fivemillimeters to about fifteen millimeters) that has been made with atrocar; as can be appreciated, smaller cannulas are usually preferred.

Endoscopic forceps that are configured for use with small cannulas(e.g., cannulas less than five millimeters) may present designchallenges for a manufacturer of endoscopic instruments.

SUMMARY

Accordingly, an end effector assembly for use with a forceps includes apair of jaw members, a knife assembly, and one or more cam assemblies.One or both of the jaw members are moveable relative to the other abouta pivot between an open position and a closed position for graspingtissue. One or both of the jaw members include a knife channel definedtherein that extends therealong. In embodiments, one or both jaw membersare adapted to connect to an electrosurgical energy source toelectrosurgically treat tissue. The pivot has first and second sectionsdefining a passage therebetween.

The knife assembly includes a knife blade and an actuation shaft. Theknife blade may be affixed to a distal end of the actuation shaft. Theknife blade is disposed distally relative to the pivot. The actuationshaft is configured for slidable translation through the passage definedbetween the first and second sections of the pivot to allow selectiveadvancement of the knife blade through the knife channel.

The one or more cam assemblies are operably coupled to the one or moremoveable jaw members and are actuatable to move one or both jaw membersbetween the open and the closed position for grasping tissuetherebetween. The one or more cam assemblies include an actuatorconfigured to move each movable jaw member between the open and theclosed position upon selective longitudinal translation thereof. Theactuator may be moveable to actuate both jaw members. The actuatorincludes one or more cam pins extending therefrom. One or both jawmembers define one or more cam slots therein such that the one or morecam slots and the one or more cam pins are configured to cooperate withone another to move each moveable jaw member. An actuator tube isoperably associated with the forceps which is configured tolongitudinally translate the actuator and permit the slidabletranslation of the actuation shaft therethrough. In one embodiment, aroll joint is operably coupled to the actuator tube and is configured tofacilitate rotational movement of the jaw members.

The end effector assembly includes a knife tube mounted to the pivotwherein the one or more cam pins are configured to slidably engage theknife tube upon the selective longitudinal translation of the actuator.The knife tube defines a recess adapted to mount each of the first andsecond sections of the pivot at the distal ends thereof. The distal endsof each of the first and second sections define a profile configured toengage the recess.

According to another aspect, a forceps includes a housing, a pair of jawmembers, a knife assembly, and one or more cam assemblies. The housinghas a shaft that extends therefrom that includes a clevis at a distalend thereof. The shaft of the housing includes an actuator tube.

The pair of jaw members are mounted to the clevis about a pivot. One orboth jaw members are moveable relative to the other about the pivotbetween an open position and a closed position for grasping tissue. Oneor both of the jaw members include a knife channel defined therein thatextends therealong. One or both of the jaw members may be adapted toconnect to an electrosurgical energy source to electrosurgically treattissue. The pivot has first and second sections defining a passagetherebetween. In embodiments, the first and second sections of the pivotare fixedly connected to the clevis.

The knife assembly includes a knife blade and an actuation shaft. Theknife blade may be affixed to a distal end of the actuation shaft. Theknife blade is disposed distally relative to the pivot. The actuationshaft is configured for slidable translation through the passage definedbetween the first and second sections of the pivot to allow selectiveadvancement of the knife blade through the knife channel.

The one or more cam assemblies are operably coupled to each moveable jawmember and are actuatable to move one or both jaw members between theopen and the closed position for grasping tissue therebetween. One ormore cam assemblies include an actuator operably coupled to the housingthat is configured to move one or both jaw members between the open andthe closed position upon selective longitudinal translation thereof. Theactuator may be moveable to actuate both jaw members. The actuatorincludes one or more cam pins extending therefrom. One or both jawmembers define one or more cam slots therein such that the one or morecam slots and the one or more cam pins are configured to cooperate withone another to move each moveable jaw member. The actuator tube isconfigured to longitudinally translate the actuator and permit theslidable translation of the actuation shaft therethrough.

The forceps includes a knife tube mounted to the pivot. The one or morecam pins are configured to slidably engage the knife tube upon theselective longitudinal translation of the actuator. The knife tubedefines a recess adapted to mount each of the first and second sectionsof the pivot at the distal ends thereof. The distal ends of each of thefirst and second sections define a profile configured to engage therecess.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of the presentdisclosure will become more apparent in light of the following detaileddescription when taken in conjunction with the accompanying drawings inwhich:

FIG. 1A is a top, perspective view of an endoscopic forceps shown in anopen configuration and including a housing, a handle assembly, a shaftand an end effector assembly according to the present disclosure;

FIG. 1B is a top, perspective view of the endoscopic forceps of FIG. 1Ashowing the end effector assembly in a closed configuration according tothe present disclosure;

FIG. 2A is an enlarged, top view of the forceps of FIG. 1A showing thedisposition of the internal components when the forceps is in an openconfiguration;

FIG. 2B is an enlarged, top view of the forceps of FIG. 1B showing thedisposition of the internal components when the forceps is in a closedconfiguration;

FIG. 3A is an enlarged, top view showing the knife actuator afteractuation;

FIG. 3B is a greatly-enlarged, side cross sectional view of the endeffector assembly showing the position of the knife after actuation;

FIG. 4A is a greatly-enlarged, perspective view of the bottom jaw of theend effector assembly with parts separated;

FIG. 4B is a greatly-enlarged, perspective view of the top jaw of theend effector assembly with parts separated;

FIG. 5 is a greatly-enlarged, perspective view of the elongated shaftfor housing various moving parts of the drive assembly and knifeassembly;

FIG. 6 is a partially exploded, perspective view of the end effectorassembly;

FIG. 7 is a top view of the end effector assembly with the upper jawmember removed;

FIG. 8 is a rear, perspective view of one of the jaw members inaccordance with an alternate embodiment of the present disclosure;

FIG. 9 is right, rear, perspective view of an end effector assemblyshown in a first position according to one embodiment of the presentdisclosure;

FIG. 10 is a left, perspective view of the end effector assembly of FIG.9 with the top jaw thereof removed for clarity and with a clevis thereofshown in phantom;

FIG. 11 is a right, perspective view of FIG. 10 with a proximal portionof the bottom jaw removed for clarity;

FIG. 12 is a right, perspective view of FIG. 11 illustrating a secondposition of the end effector assembly of FIG. 9 ; and

FIG. 13 is a right, perspective view of one embodiment of an endeffector assembly.

DETAILED DESCRIPTION

Detailed embodiments of the present disclosure are disclosed herein;however, the disclosed embodiments are merely exemplary of thedisclosure, which may be embodied in various forms. Therefore, specificstructural and functional details disclosed herein are not to beinterpreted as limiting, but merely as a basis for the claims and as arepresentative basis for teaching one skilled in the art to variouslyemploy the present disclosure in virtually any appropriately detailedstructure.

As noted above, it may prove useful in the arts to provide anelectrosurgical apparatus that is suitable for use with various accessports, including but not limited to those that are greater than and/orless than five millimeters. With this purpose in mind, the presentdisclosure includes an electrosurgical forceps that includes a driveassembly operatively coupled to one or more jaw members associated withthe end effector assembly of the electrosurgical forceps. The driveassembly is configured to move the jaw members from an open to a closedconfiguration such that when actuated, the jaw members form a closedloop electrical circuit such that a desired tissue effect (e.g., tissueseal) may be achieved.

Turning now to FIGS. 1A and 1B, one embodiment of an electrosurgicalforceps 10 is shown for use with various surgical procedures andgenerally includes a housing 20, a handle assembly 30, a rotatingassembly 80, a knife trigger assembly 70 and an end effector assembly100 which mutually cooperate to grasp, seal and divide tubular vesselsand vascular tissue. Although the majority of the figure drawings depicta forceps 10 for use in connection with endoscopic or laparoscopicsurgical procedures, the present disclosure may be used for moretraditional open surgical procedures. For the purposes herein, theforceps 10 is described in terms of an endoscopic or laparoscopicinstrument; however, it is contemplated that an open version of theforceps may also include the same or similar operating components andfeatures as described below.

Forceps 10 includes a shaft 12 that has a distal end 16 dimensioned tomechanically engage the end effector assembly 100 and a proximal end 14that mechanically engages the housing 20. Details of how the shaft 12connects to the end effector assembly 100 are described in more detailbelow. The proximal end 14 of shaft 12 is received within the housing 20and the connections relating thereto are also described in detail below.In the drawings and in the descriptions that follow, the term“proximal”, as is traditional, will refer to the end of the forceps 10that is closer to the user, while the term “distal” will refer to theend that is farther from the user.

Forceps 10 also includes an electrosurgical cable 310 that may beinternally divided into two or more leads which may connect the forceps10 to a source of electrosurgical energy, e.g., a generator. Generatorssuch as those sold by Covidien, located in Boulder, Colo. may be used asa source of both bipolar electrosurgical energy for sealing vessel andvascular tissues as well as monopolar electrosurgical energy which istypically employed to coagulate or cauterize tissue. It is envisionedthat the generator may include various safety and performance featuresincluding isolated output, impedance control and/or independentactivation of accessories.

Handle assembly 30 includes two movable handles 30 a and 30 b disposedon opposite sides of housing 20. Handles 30 a and 30 b are movablerelative to one another to actuate the end effector assembly 100 asexplained in more detail below with respect to the operation of theforceps 10.

Rotating assembly 80 is mechanically coupled to housing 20 and isrotatable approximately 90 degrees in either direction about alongitudinal axis “A.” Rotating assembly 80, when rotated, rotates shaft12, which, in turn, rotates end effector assembly 100. Such aconfiguration allows end effector assembly 100 to be rotatedapproximately 90 degrees in either direction with respect to housing 20.

As mentioned above, end effector assembly 100 is attached at the distalend 16 of shaft 12 and includes a pair of opposing jaw members 110 and120 (see FIG. 6 ). Handles 30 a and 30 b of handle assembly 30ultimately connect to drive assembly 60 (see FIG. 2A) which, together,mechanically cooperate to impart movement of the jaw members 110 and 120from a first, open position wherein the jaw members 110 and 120 aredisposed in spaced relation relative to one another, to a second,clamping or closed position wherein the jaw members 110 and 120cooperate to grasp tissue therebetween.

Turning now to the more detailed features of the present disclosure asdescribed with respect to FIGS. 1A-8 , handles 30 a and 30 b eachinclude an aperture 33 a and 33 b, respectively, defined therein whichenables a user to grasp and move each respective handle 30 a and 30 brelative to one another. Handles 30 a and 30 b also includeergonomically-enhanced gripping elements 39 a and 39 b, respectively,disposed along an outer edge thereof which are designed to facilitategripping of the handles 30 a and 30 b during activation. It isenvisioned that gripping elements 39 a and 39 b may include one or moreprotuberances, scallops and/or ribs to enhance gripping.

As best illustrated in FIG. 1A, handles 30 a and 30 b are configured toextend outwardly on opposite sides from a transverse axis “B” definedthrough housing 20 which is perpendicular to longitudinal axis “A”.Handles 30 a and 30 b are movable relative to one another in a directionparallel to axis “B” to open and close the jaw members 110 and 120 asneeded during surgery. Details relating to the inner-working componentsof forceps 10 are disclosed in commonly-owned U.S. patent applicationSer. No. 11/540,335. This forceps style is commonly referred to as an“in-line” or hemostat style forceps. In-line hemostats or forceps aremore commonly manufactured for open surgical procedures and typicallyinclude a pair of shafts having integrally coupled handles which aremovable relative to one another to open and close the jaw membersdisposed at the distal end thereof.

As best seen in FIGS. 2A and 2B, the distal end of each handle 30 a and30 b is selectively moveable about pivot pins 34 a and 34 b attached toa distal end 21 of the housing 20 to actuate the jaw members 110 and120. Movement of the handles 30 a and 30 b away from one another (andthe housing 20) unlocks and opens the handles 30 a and 30 b and, inturn, the jaw members 110 and 120 for subsequent grasping or re-graspingof tissue. In one embodiment, the handles 30 a and 30 b may be biased inan open configuration to facilitate handling and manipulation of thejaws within an operative field. Various spring-like mechanisms arecontemplated which may be utilized to accomplish this purpose.

Movable handles 30 a and 30 b are designed to provide a distinctlever-like mechanical advantage over conventional handle assemblies. Theenhanced mechanical advantage for actuating the jaw members 110 and 120is gained by virtue of the unique position and combination of severalinter-cooperating elements which reduce the overall user forcesnecessary to obtain and maintain the jaw members 110 and 120 under idealoperating pressures of about 3 kg/cm2 to about 16 kg/cm2. Detailsrelating to the working components the handle assembly and driveassembly are disclosed in above-mentioned U.S. patent application Ser.No. 11/540,335. In other words, it is envisioned that the combination ofthese elements and their positions relative to one another enables theuser to gain lever-like mechanical advantage to actuate the jaw members110 and 120 enabling the user to close the jaw members 110 and 120 withlesser force while still generating the required forces necessary toeffect a proper and effective tissue seal.

As shown best in FIGS. 4A, 4B, 5 and 6 , the end effector assembly 100is designed as a bilateral assembly, i.e., both jaw members 110 and 120pivot relative to one another about a pivot pin 185 disposedtherethrough. A unilateral end effector assembly is also envisioned. Endeffector assembly 100 further includes a knife guide 133 that houses theknife blade 190 for translation therethrough. Knife guide 133 isassembled with flanges 113 and 123 to allow pivotable movement of theflanges 113 and 123 about a pivot pin 185 disposed between the jawmembers 110 and 120 upon translation of a drive pin 180 as explained inmore detail below.

More particularly, jaw members 110 and 120 include proximal flanges 113and 123, respectively, which each include an elongated angled slot 181 aand 181 b, respectively, defined therethrough. Drive pin 180 mounts jawmembers 110 and 120 and knife guide 133 to the end of a rotating shaft18 and within a cavity 17′ defined at the distal ends 17 a and 17 b ofdrive actuator or sleeve 17 (See FIG. 5 ). Knife guide 133 includes anelongated slot 181 c defined therethrough, configured for accepting thedrive pin 180 and for allowing translation of the drive pin 180 withinslots 181 a-181 c, which pivots the jaw members 110 and 120 relative toone another for grasping tissue. Knife guide 133 may also provide aunique safety feature for the forceps 10 as described in more detailbelow.

Upon actuation of the drive assembly 60, the drive sleeve 17reciprocates which, in turn, causes the drive pin 180 to ride withinslots 181 a and 181 b to open and close the jaw members 110 and 120 asdesired and similarly causes the drive pin 180 to ride within slot 181 cof knife guide 133. The jaw members 110 and 120, in turn, pivot aboutpivot pin 185 disposed through respective pivot holes 186 a and 186 bdefined within flanges 113 and 123, the jaw members 110 and 120 and hole186 c disposed within knife guide 133. Upon actuation, knife guide 133remains oriented in alignment with the shaft 12 as the jaws move aboutpivot pin 185 (See FIG. 6 ). As can be appreciated, squeezing handles 30a and 30 b toward the housing 20 pulls drive sleeve 17 and drive pin 180proximally to close the jaw members 110 and 120 about tissue graspedtherebetween and pushing the sleeve 17 distally opens the jaw members110 and 120 for grasping purposes.

Flanges 113 and 123 of j aw members 110 and 120, respectively, arepositioned in an abutting relationship with one another and knife guide133 is positioned adjacent to flanges 113 and 123. Flanges 113, 123 andknife guide 133 are assembled and engaged via pivot pin 185 disposedthrough apertures 186 a, 186 b, and 186 c, respectively. Further,flanges 113, 123 are pivotable about one another via drive pin 180disposed through slots 181 a and 181 b of flanges 113, 123,respectively. A knife path 138 may be defined between flange 113 andknife guide 133, as shown in FIGS. 6 and 7 . The knife path 138longitudinally aligns with knife channels 115 a and 115 b defined withinjaw members 110 and 120, such that knife blade 190 travels in asubstantially straight path through knife path 138 and, further, throughknife channels 115 a and 115 b.

Alternatively, the orientation of flanges 113 and 123 may be reversed,with knife path 138 being defined between flange 123 and blade guide133. In contrast to prior known designs, the abutting relationshipbetween flanges 113 and 123 (in either orientation) strengthens the jawflanges 113 and 123 since a blade path or blade channel does not need tobe defined therebetween but, rather, is defined on an exterior side ofone of the flanges 113 and 123. Thus, the knife 190 travels between theblade guide 133 and the flanges 113 and 123 and not between flanges. Bymanufacturing the knife path 138 on either side of the flanges 113 and123, jaw splay may also be more easily controlled and tighter tolerancesmay be employed during the manufacturing process, thereby allowingtighter tolerances on certain features of the jaw member 110 and 120resulting in better overall performance.

For example, the knife channels 115 a and 115 b defined within the jawmembers 110 and 120, respectively, may be more precisely aligned withless splay between the jaw members 110 and 120, thereby facilitatingknife blade 190 translation. Moreover, the strength of the flanges 113and 123 is enhanced as well as the union therebetween, e.g.,flat-on-flat abutting flange surfaces have more surface contact makingthe union therebetween stronger. The knife guide 133 may also beconfigured to pre-load jaw members 110 and 120 to help ensure properalignment of knife channel halves 115 a and 115 b upon closing of thejaw members 110 and 120 as explained in more detail below.

As best shown in FIG. 6 , blade guide 133 may include a blade stop orhook 135 disposed at a distal end thereof. The blade stop 135 may beintegrally associated with the knife guide 133 (FIG. 6 ), the purpose ofwhich is explained immediately below, or pivotably engaged with theknife guide 133, the purpose of which is explained with reference toFIG. 9 . The relationship between flanges 113 and 123 and blade guide133 is established by pivot pin 185 disposed through apertures 186 a,186 b, and 186 c, respectively, and by drive pin 180 disposed throughslots 181 a, 181 b and 181 c, respectively. Accordingly, when jawmembers 110, 120 are in a first, or open, position, knife guide 133pivots such the blade stop 135 interferes with the knife path 138,thereby preventing distal translation of knife blade 190. In oneembodiment, this may be accomplished by the knife guide 133 including anelongated slot 181 c that is cammed when the drive pin 180 is biased ina distal-most position such that the knife guide 133 and blade stop 135pivot thereby obstructing the knife path 138.

When handles 30 a and 30 b are squeezed toward the housing 20, drivesleeve 17 and drive pin 180 are pulled proximally to close the jawmembers 110 and 120, which also pivots the knife guide 133 so that theblade stop 135 no longer obstructs or interferes with the knife path138. Thus, in this embodiment, the knife guide 133, by virtue of theblade stop 135, prevents distal advancement of knife blade 190 when jawmembers 110 and 120 are in the first, open position and permits distaladvancement of knife blade 190 when jaw members 110 and 120 are in thesecond, closed position.

Alternatively, a hook (not shown) may be disposed on either of flanges113 or 123. The hook would operate in substantially the same manner asthe blade stop 135 disposed on the blade guide 133 in the embodimentdiscussed above. Accordingly, as jaw members 110, 120 are opened, thehook on flange 113 or 123 is pivoted into the path of knife blade 190,thereby preventing distal translation of knife blade 190. When handles30 a and 30 b are squeezed toward the housing 20, drive sleeve 17 anddrive pin 180 are pulled proximally to close the jaw members 110 and120. The pulling of drive pin 180 also pivots flanges 113 and 123,thereby closing the jaw members 110 and 120 and as a result, the hook ispivoted out of the path of knife blade 190.

As best shown in FIG. 4B, jaw member 110 also includes a support base119 that extends distally from flange 113 and that is configured tosupport an insulative plate 119′ thereon. Insulative plate 119′, inturn, is configured to support an electrically conductive tissueengaging surface or sealing plate 112 thereon. Sealing plate 112 may beaffixed atop the insulative plate 119′ and support base 119 in anysuitable manner, e.g., snap-fit, over-molding, stamping, ultrasonicallywelded, etc. Support base 119 together with the insulative plate 119′and electrically conductive tissue engaging surface 112 are encapsulatedby an outer insulative housing 114. Outer housing 114 includes a cavity114 a that is dimensioned to securely engage the electrically conductivesealing surface 112 as well as the support base 119 and insulative plate119′. This may be accomplished by stamping, by overmolding, byovermolding a stamped electrically conductive sealing plate and/or byovermolding a metal injection molded seal plate. All of thesemanufacturing techniques produce jaw member 110 having an electricallyconductive surface 112 that is substantially surrounded by an insulatingsubstrate 114.

The electrically conductive surface or sealing plate 112 and the outerhousing 114, when assembled, form longitudinally-oriented knife channel115 a defined therethrough for reciprocation of the knife blade 190. Itis envisioned that the knife channel 115 a cooperates with correspondingknife channel 115 b defined in jaw member 120 to facilitate longitudinalextension of the knife blade 190 along a preferred cutting plane toeffectively and accurately separate the tissue along the formed tissueseal. As discussed above, when knife blade 190 is deployed, at least aportion of knife blade 190 advances through knife path 138 and intoknife channels 115 a and 115 b. In addition to the blade stop 135,handle 30 a may includes a lockout flange (not shown) which preventsactuation of the knife assembly 70 when the handle 30 a is open thuspreventing accidental or premature activation of the knife blade 190through the tissue. A more detailed discussion of the lockout flange isdiscussed in above-mentioned U.S. patent application Ser. No.11/540,335.

As explained above and as illustrated in FIGS. 4A and 4B, in oneembodiment, the knife channel 115 is formed when the jaw members 110 and120 are closed. In other words, the knife channel 115 includes two knifechannel halves—knife channel half 115 a disposed in sealing plate 112 ofjaw member 110 and knife channel half 115 b disposed sealing plate 122of jaw member 120. It is envisioned that the knife channel 115 may beconfigured as a straight slot with no degree of curvature which, inturn, causes the blade 190 to move through the tissue in a substantiallystraight fashion. Alternatively, and as shown, the knife channel 115 maybe curved, which has certain surgical advantages. In the particularembodiment shown in FIGS. 6 and 7 , the knife channel 115 (knife channel115 a shown) is curved and is offset from the centerline or longitudinalaxis “A” of the forceps 10 by a distance “X” (See FIGS. 7 and 8 ). Thisoffset distance “X” may be in the range of about 0.010 inches to about0.040 inches.

The offset orientation of the knife blade 190 (by virtue or the knifeguide 133 being assembled on one side of the flanges 113 and 123 allowsthe knife blade to enter the knife channel 115 in a substantiallystraight orientation thereby facilitating separation of tissue.Moreover, the knife blade 190 travels in a substantially straight mannerthrough most of the knife channel 115 and is only forced to bend aroundthe knife channel 115 towards a distal end of the jaw members 110 and120. Further, the offset orientation of the knife channel, e.g., knifechannel 115 b, and the disposition of the knife blade 190 travelingthrough the knife guide 133 also enhances the cutting effect and reducesthe chances of the knife blade 190 binding during translation (extensionor retraction).

As mentioned above, when the jaw members 110 and 120 are closed abouttissue, knife channels 115 a and 115 b form a complete knife channel 115to allow longitudinal extension of the knife blade 190, from the knifepath 138, in a distal fashion to sever tissue along a tissue seal. Knifechannel 115 may be completely disposed in one of the two jaw members,e.g., jaw member 120, depending upon a particular purpose. It is alsoenvisioned that jaw member 120 may be assembled in a similar manner asdescribed above with respect to jaw member 110.

Referring now to FIGS. 6 and 8 , electrical lead or wire 126 is shownextending from shaft 12 through knife housing 133 and entering wire tube125 of jaw members 120. Wires 116 and 126 are used to supply electricalenergy to electrically conductive sealing surfaces 112 and 122 of jawmembers 110 and 120, respectively. In the embodiment of FIG. 6 , knifehousing 133 also acts as a wire guide, configured to guide wires 116 and126 to jaw members 110 and 120. Electrical leads or wires 116 and 126are protected by knife housing 133. Wire tube 125 (FIG. 8 ) of jawmember 120, may be offset from a longitudinal axis “Y” of the forceps 10in the same direction as the offset knife channel 115 b, such that knifechannel 115 b is disposed above the wire tube 125. The offset “X” of theknife channel, e.g., knife channel 115 b, and the offset “Y” of thedisposition of the electrical lead or wire 126 relative to longitudinalaxis “A” may be different or the same depending upon a particularpurpose or to facilitate manufacturing. For example, as mentioned above,the offset distance “X” may be in the range of about 0.010 inches toabout 0.040 inches whereas the offset distance “Y” may be in the rangeabout 0.040 inches to about 0.140 inches. In addition, particular “X”and “Y” configurations may be as follows: When “X” is about 0.010 inches“Y” may be about 0.040 inches; when “X” is about 0.017 inches “Y” may beabout 0.070 inches; and when “X” is about 0.034 inches “Y” may be about0.140 inches. Other configurations and offsets for “X” and “Y” are alsocontemplated and within the scope of this disclosure.

Referring now to FIGS. 9-12 , one embodiment of an end effector assembly400 for use with forceps 10 includes a pair of jaw members 402, 404, aknife assembly 410, and a cam assembly 420.

One or both jaw members 402, 404 are moveable relative to the otherabout a pivot 440 operably associated with the forceps 10. One or bothjaw members 402, 404 are moveable between an open position (FIGS. 9-11 )and a closed position (FIG. 12 ) for grasping tissue. One or both of thejaw members 402, 404 include a knife channel 406 defined therein thatextends therealong. One or both of the jaw members 402, 404 may beadapted to connect to an electrosurgical energy source toelectrosurgically treat tissue.

The knife assembly 410 includes a knife blade 412 and an actuation shaft414. The knife blade 412 may be affixed to a distal end of the actuationshaft 414. The actuation shaft 414 is operably associated with the knifetrigger assembly 70 of forceps 10 (FIG. 1 ). The knife blade 412 isdisposed distally relative to the pivot 440. The actuation shaft 414 isconfigured for slidable translation through the pivot 440 to allowselective advancement of the knife blade 412 through the knife channel406 upon activation by the knife trigger assembly 70.

The cam assembly 420 is operably coupled to each moveable jaw member402, 404 and is actuatable to move one or both jaw members 402, 404between the open and the closed position for grasping tissuetherebetween. The cam assembly 420 includes an actuator clevis 422operably coupled to a support clevis 430 operably associated with thehousing 20. The cam assembly 420 is configured to move one or both jawmembers 402, 404 between the open and the closed position upon selectivelongitudinal translation thereof. The actuator clevis 422 may bemoveable via an actuator tube 450 operably associated with the shaft 12extending from the housing 20 to actuate both jaw members 402, 404.

The pair of jaw members 402, 404 are mounted to the support clevis 430about the pivot 440. The support clevis 430 defines an actuator bore 432and an actuator tube bore 434 for facilitating the slidable translationof the actuator clevis 422 and the actuator tube 450 therethrough. Withreference to FIG. 9 , cable channels 470, 472, etc. may also be definedthrough support clevis 430 for receiving one or more of the leads of theelectrosurgical cable 310 (FIG. 1 ) therethrough.

The pivot 440 has first and second sections 442, 444 defining a passage446 therebetween configured to permit the actuation shaft 414 toslidably translate therethrough. In some embodiments, the first andsecond sections 442, 444 of the pivot 440 are fixedly connected to thesupport clevis 430. The support clevis 430 is mounted to the distal endof the actuator tube 450. The actuator tube 450 is operably associatedwith the drive assembly 60 for longitudinally translating the actuatortube 450. The actuator tube 450 is configured to slidingly receive theknife assembly 410 therein.

The actuator clevis 422 includes one or more cam pins 424, 426 extendingtherefrom. One or both jaw members 402, 404 define one or more cam slots403, 405 therein such that the one or more cam slots 403, 405 and theone or more cam pins 424, 426 are configured to cooperate with oneanother to move each moveable jaw member 402, 404. The actuator tube 450is configured to longitudinally translate the actuator clevis 422 andpermit the slidable translation of the actuation shaft 414 therethroughfor facilitating the translation of the knife blade 412. The actuatortube 450 slidably translates along a knife tube 460 mounted to the pivot440 between the first and second sections 442, 444.

The one or more cam pins 424, 426 are configured to slidably engage theknife tube 460 upon the selective longitudinal translation of theactuator clevis 422. The distal ends 424 d, 426 d of the cam pins 424,426 are configured to slidably engage the outer surface of the knifetube 460. As illustrated in FIGS. 11 and 12 , the distal ends 424 d, 426d of the cam pins 424, 426 define a pin profile that may be generallycrescent-shaped for cooperating with the generally circularly-shapedouter surface of the knife tube 460. The knife tube 460 and the pinprofiles may have any suitable cross-sectional shape (e.g., circular ornon-circular). The knife tube 460 defines a recess 462 adapted to mounteach of the first and second sections 442, 444 of the pivot 440 at thedistal ends 442 d, 444 d thereof. The distal ends 442 d, 444 d of eachof the first and second sections 442, 444 define a profile configured tofixedly engage the recess 462. The profiles of both the distal ends 442d, 444 d of the first and second sections 442, 444 define the passage446 between each section 442, 444 for engaging the recess 462 of theknife tube 460. The passage 446 and the recess 462 may define anysuitable cross-sectional shape (e.g., circular or non-circular). Asillustrated in the embodiment of FIG. 11 , the profiles of the first andsecond sections 442, 444 are each generally crescent-shaped to fixedlyengage the circumferential groove that defines the recess 462 so thatfirst and second sections 442, 444 provide a stationary pivot aboutwhich jaw members 402, 404 move.

In operation, upon actuation of the movable handles 30 a and 30 b, thedrive assembly 60 slidably longitudinally translates the actuator tube450 through the actuator tube bore 434 of the support clevis 430. Thetranslation of the actuator tube 450 effectuates the longitudinaltranslation of the actuator clevis 422 through the actuator bore 432 ofthe support clevis 430. As the actuator clevis 422 translates, each campin 424, 426 slides within each respective cam slot 403, 405 and alongthe outer surface of the knife tube 460. When each cam pin 424, 426translates through each respective cam slot 403, 405, the jaw members402, 404 translate between the first position and the second position.In effect, each respective jaw member 402, 404 rotates about the pivot440 in response to the longitudinal translation of the actuator clevis422. Upon actuation of the knife trigger assembly 70, the actuationshaft 414 translates through the actuator tube 450 and the knife tube460 such that the knife blade 412 is advanced through the knife channel406 of the jaw members 402, 404.

With reference to FIG. 13 , one embodiment of an end effector assembly500 for use with forceps 10 includes a roll joint 510 secured to thedistal end of the support clevis 430 and operably coupled to theactuator tube 450 for facilitating the rotational movement of the jawmembers 402, 404. The roll joint 510 includes a stationary portion 510 aand rotatable portion 510 b. The stationary portion 510 a is fixedlycoupled to the handle assembly 30. The rotatable portion 510 b isoperably coupled to the stationary portion 510 a and the actuator tube450. The rotatable portion 510 b includes one or more moveableinterfaces 512 (e.g., one or more bearings, bushings, etc.) securedthereto. Each movable interface 512 is configured to permit relativerotation between the stationary portion 510 a and the rotatable portion510 b.

In operation, the actuator tube 450 is rotated which, in turn, rotatesthe rotatable portion 510 b in response thereto. With the actuator tube450 fixedly mounted to the rotatable portion 510 b and radially movablewithin the stationary portion 510 a, the actuator tube 450 transmitstorque to the jaw members 402, 404 via the roll joint 510 upon therotational movement of the actuator tube 450. In this manner, the jawmembers 402, 404 may be radially rotated about the longitudinal axis “A”while the handle assembly 30 remains stationary.

With these embodiments, the distance to the pivot point is significantlyreduced which facilitates assembly and ease of use. In certainembodiments, this shortened distance to the pivot point facilitatesarticulation of the end effector.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely asexemplifications of particular embodiments. Those skilled in the artwill envision other modifications within the scope and spirit of theclaims appended hereto.

What is claimed is:
 1. An end effector assembly, comprising: a supportclevis including a proximal base and first and second distal armsextending distally from the proximal base in spaced-apart relationrelative to one another to define a volume therebetween, the proximalbase defining a longitudinal bore and each of the first and seconddistal arms defining a transverse pivot aperture; first and second jawmembers each including a distal body and a proximal flange, the distalbodies of the first and second jaw members extending distally from thefirst and second distal arms of the support clevis, the proximal flangesof the first and second jaw members disposed at least partially withinthe volume defined between the first and second distal arms of thesupport clevis, the proximal flanges of the first and second jaw memberseach defining a pivot aperture and a cam slot; a pivot extending atleast partially through the pivot aperture of the first distal arm ofthe support clevis, the pivot aperture of the proximal flange of thefirst jaw member, the pivot aperture of the proximal flange of thesecond jaw member, and the pivot aperture of the second distal arm ofthe support clevis to pivotably couple the proximal flanges of the firstand second jaw members to one another and the support clevis; and a camslidably disposed within the volume defined between the distal arms ofthe support clevis and longitudinally confined therein distally via thepivot and proximally via the proximal base of the support clevis, thecam including first and second cam pins, the first cam pin directlyoperably engaged within the cam slot of the proximal flange of the firstjaw member and the second cam pin directly operably engaged within thecam slot of the proximal flange of the second jaw member, the first andsecond cam pins fixed relative to one another, wherein longitudinaltranslation of the cam within the volume defined between the first andsecond distal arms of the support clevis slides the first and second campins through the cam slots of the proximal flanges of the first andsecond jaw members, respectively, to pivot the distal bodies of thefirst and second jaw members relative to one another and the supportclevis between a spaced-apart position and an approximated position. 2.The end effector assembly according to claim 1, wherein at least aportion of the cam defines a dimension larger than a diameter of thelongitudinal bore of the proximal base of the support clevis to inhibitproximal passage of the cam through the proximal base of the supportclevis.
 3. The end effector assembly according to claim 1, wherein thecam is an actuator clevis.
 4. The end effector assembly according toclaim 1, further comprising: an actuator extending through thelongitudinal bore of the proximal base of the support clevis andoperably coupled to the cam, wherein translation of the actuator throughthe longitudinal bore of the proximal base of the support clevistranslates the cam longitudinally within the volume defined between thefirst and second distal arms of the support clevis to thereby slide thefirst and second cam pins through the cam slots of the proximal flangesof the first and second jaw members, respectively, to pivot the distalbodies of the first and second jaw members relative to one another andthe support clevis between the spaced-apart position and theapproximated position.
 5. The end effector assembly according to claim1, wherein the distal body of each of the first and second jaw membersincludes a support base, an electrically-conductive plate, and an outerhousing securing the support base and the electrically-conductive platewith one another.
 6. The end effector assembly according to claim 5,wherein the support bases of the distal bodies of the first and secondjaw members are formed with the proximal flanges of the first and secondjaw members, respectively.
 7. The end effector assembly according toclaim 5, wherein the electrically-conductive plates of the distal bodiesof the first and second jaw members oppose one another in theapproximated position of the distal bodies.
 8. The end effector assemblyaccording to claim 7, further comprising first and second electricalwires attached to the electrically-conductive plates of the distalbodies of the first and second jaw members, respectively, and configuredto supply electrosurgical energy thereto.
 9. The end effector assemblyaccording to claim 5, wherein the electrically-conductive plate of thedistal body of each of the first and second jaw members defines a knifechannel therethrough, each knife channel having an open proximal end.10. The end effector assembly according to claim 9, wherein the proximalflanges of the first and second jaw members are laterally offsetrelative to the open proximal ends of the knife channels of theelectrically-conductive plates of the distal bodies of the first andsecond jaw members, respectively.
 11. The end effector assemblyaccording to claim 1, further comprising: a knife blade positioneddistally of the pivot and configured for longitudinal translationbetween the distal bodies of the first and second jaw members in theapproximated position of the distal bodies.
 12. The end effectorassembly according to claim 11, further comprising: a knife actuatorextending through the longitudinal bore of the proximal base of thesupport clevis, the cam, and the pivot, the knife actuator coupled tothe knife blade distally of the pivot and configured to longitudinallytranslate through the longitudinal bore of the proximal base of thesupport clevis, the cam, and the pivot to translate the knife bladebetween a retracted position and an extended position relative to thedistal bodies of the first and second jaw members.
 13. The end effectorassembly according to claim 1, further comprising a joint disposed at aproximal end portion of the proximal base of the support clevis.
 14. Theend effector assembly according to claim 13, wherein the joint includesa movable portion and a stationary portion, the movable portion of thejoint fixed to the proximal end portion of the proximal base of thesupport clevis such that the support clevis is movable relative to thestationary portion of the joint.
 15. The end effector assembly accordingto claim 14, wherein the joint is a roll joint such that movement of themovable portion of the joint relative to the stationary portion of thejoint is rotational motion.
 16. The end effector assembly according toclaim 13, wherein the joint includes one or more movable interfaces. 17.An end effector assembly, comprising: a joint including a stationary endportion and a movable end portion movable relative to the stationaryportion; a support clevis fixed to and extending distally from themovable end portion of the joint, the support clevis including aproximal base and first and second distal arms extending distally fromthe proximal base in spaced-apart relation relative to one another;first and second jaw members at least partially disposed between andextending distally from the first and second distal arms of the supportclevis; a pivot pivotably coupling the first and second jaw members toone another and the support clevis; and a cam slidably disposed betweenthe distal arms of the support clevis and longitudinally confinedtherein distally via the pivot and proximally via the proximal base ofthe support clevis, the cam including first and second cam pins, thefirst cam pin directly operably engaged within a cam slot of the firstjaw member and the second cam pin directly operably engaged within a camslot of the second jaw member, the first and second cam pins fixedrelative to one another, wherein longitudinal translation of the camslides the first and second cam pins through the cam slots of the firstand second jaw members, respectively, to pivot the first and second jawmembers relative to one another and the support clevis between aspaced-apart position and an approximated position.
 18. The end effectorassembly according to claim 17, wherein the joint is a roll joint suchthat movement of the movable end portion of the joint relative to thestationary end portion of the joint is rotational motion.
 19. The endeffector assembly according to claim 17, wherein the joint includes oneor more movable interfaces to enable movement of the movable end portionof the joint relative to the stationary end portion of the joint. 20.The end effector assembly according to claim 17, further comprising: anactuator extending through the joint and the proximal base of thesupport clevis to operably coupled to the cam, wherein translation ofthe actuator through the joint and the proximal base of the supportclevis translates the cam longitudinally between the first and seconddistal arms of the support clevis to thereby slide the first and secondcam pins through the cam slots of the first and second jaw members,respectively, to pivot the first and second jaw members relative to oneanother and the support clevis between the spaced-apart position and theapproximated position.